Turn WebAssembly/Emscripten support into a dedicated architecture

Author: martin-frbg

common.h

@@ -386,9 +386,11 @@ typedef int blasint;
 #endif
 #endif
 
-#ifdef __EMSCRIPTEN__
+#if defined(ARCH_WASM)
+#ifndef YIELDING
 #define YIELDING
 #endif
+#endif
 
 #if defined(_MSC_VER) && !defined(__clang__)
 #undef YIELDING // MSVC doesn't support assembly code
@@ -498,6 +500,10 @@ please https://github.com/xianyi/OpenBLAS/issues/246
 #include "common_csky.h"
 #endif
 
+#ifdef ARCH_WASM
+#include "common_wasm.h"
+#endif
+
 #ifndef ASSEMBLER
 #ifdef OS_WINDOWSSTORE
 typedef char env_var_t[MAX_PATH];